\ 
Pl.cell.aph. 1. HYDROPHYTE. 279 
Thallus mostly branched; branches blad- 
EE scale eae i Se 5 ola eiagg Freneys gd ~-.. WAUCHERIA. 10. 
Thallus entangled, ; in a determinate ne m; 
branches clublike . Tk ee oss Ce UE IE bx 
E. Thallus jointed, filamentous; filaments flat, brittle. 
Diatomidez. 
Joints not banded; sporidia in transverse 
Bess... « eat Mae oo os weeeeees FRAGILARIA. 12. 
Joints banded transversely, with a cen- 
Co DS OT a Ss ao es delsige's)' + DEDDULPHIA. PS 
Joints banded longitudinally Used) acta etare Diatoma. 14. 
F. Thallus jointed, filamentous ; ilernents cylindrical, 
coupling. Conjugatideze. 
Filamenis parallel; granules es .. Congucata. 15. 
Fil. parallel ; aranules 2-dotted . ... ZYGNEMA. 16. 
Fil. bent; granules scattered ; 
spore elliptical, in the jomt....5 008 .... CHOASPES. 17. 
Fil, bent; granules scattered ; ’ 
spore cruciform, i in the contracted joint ... AGaRpIA. 18. 
Fil., bent; granules scattered ; 
spore on dede ; the transverse tubes «2. SERPENTINA. 19. 
G. Thallus cylindrical, anastomosing, netlike. Wydro- 
dictyanideze. 
Filaments anastomosing; spore netlike 
Hypropicryox. 20. 
H. Thallus cylindrical, simple, or br bathe not coupling, 
nor anastomosing. Confervider. 
Thallus from a common base; 
branches pointed, pellucid ..... ... Myriopactyton. 22. 
‘Thallus from a common base; 
branches obtuse, clublike ..... bite o 6 deta ic uRiA REESE Au: Sem 
Thallus from a common axis ..... . CHETOPHORA. 21. 
* Thallus uniform, simple or branched .. CoNFERVA. 25. 
Thallus difform; branches ee 
shaped, jointed .................. DRAPARNALDIA. 24. 
